Finding and extracting the data

Suppose we'll get a worksheet similar to the following:

Scenario:

The data is in a worksheet called "Data" (very original)
The worksheet has two tables separated by at least one empty row.
The first table doesn't have to start on the first row nor the first column.
The table IDs on both tables are always present.
The column names of the first table can change but their order is fixed.
The column names of the second table are fixed but the column order can change.

Task:

Extract two lists of category and company names.

Code:

private static void Main()
{
List<String> categories;
List<String> companies;
ExtractCategoriesCompanies("NorthwindData.xlsx", out categories, out companies);
// Do something with the categories and companies
}
private static void ExtractCategoriesCompanies(string northwinddataXlsx, out List<string> categories, out List<string> companies)
{
categories = new List<string>();
const int coCategoryId = 1;
const int coCategoryName = 2;
var wb = new XLWorkbook(northwinddataXlsx);
var ws = wb.Worksheet("Data");
// Look for the first row used
var firstRowUsed = ws.FirstRowUsed();
// Narrow down the row so that it only includes the used part
var categoryRow = firstRowUsed.RowUsed();
// Move to the next row (it now has the titles)
categoryRow = categoryRow.RowBelow();
// Get all categories
while (!categoryRow.Cell(coCategoryId).IsEmpty())
{
String categoryName = categoryRow.Cell(coCategoryName).GetString();
categories.Add(categoryName);
categoryRow = categoryRow.RowBelow();
}
// There are many ways to get the company table.
// Here we're using a straightforward method.
// Another way would be to find the first row in the company table
// by looping while row.IsEmpty()
// First possible address of the company table:
var firstPossibleAddress = ws.Row(categoryRow.RowNumber()).FirstCell().Address;
// Last possible address of the company table:
var lastPossibleAddress = ws.LastCellUsed().Address;
// Get a range with the remainder of the worksheet data (the range used)
var companyRange = ws.Range(firstPossibleAddress, lastPossibleAddress).RangeUsed();
// Treat the range as a table (to be able to use the column names)
var companyTable = companyRange.AsTable();
// Get the list of company names
companies = companyTable.DataRange.Rows()
.Select(companyRow => companyRow.Field("Company Name").GetString())
.ToList();
}